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WaterOperator.org Blog

Protecting a Septic System During and After a Flood

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When a home or the area surrounding it floods, the septic system is at risk of becoming waterlogged. This could be from a leak in the lid, rising groundwater that enters into the system, or an over-saturated drainfield that can't properly drain. A flooded septic system may lead to sewage backing up into the home and cause serious problems for the homeowner. 

Septic tanks may not always experience damage just because there is flooding, but any existing leaks in the system will allow floodwater, silt, and debris to enter the system. This presents a big problem since the extra dirt and debris can cause clogging. Extra water entering the septic system can also cause the floating solids to rise up and plug the pipes. The U.S. Environmental Protection Agency has information on what to do after a flood to ensure your septic system is protected. Below we have summarized this information with a list of dos & don'ts:

Septic System Flooding Dos & Dont's

Do! Don't!
Conserve water as much as possible Don't drink well water until it is tested
Cut back on showers, laundry, running the dishwasher, and flushing the toilet Don't compact the soil over the drainfield by driving heavy machinery over the area
Clean affected areas within the home with a solution of 1/2 cup bleach to 1 gallon of water if there are backups Don't use the system until water in the soil absorption field is lower than the water level around the house
Have the system professionally inspected and serviced if there is suspected damage Don't attempt to clean or repair the septic tank yourself
Ensure the manhole cover is secure and inspection ports have not been blocked or damaged Don't open the septic system for pumping while high groundwater conditions remain
Pump both the tank and the lift station as soon as possible after the flood subsides Don't dig into the tank or drainfield area while the soil is still wet
Examine all electrical connections before restoring electricity to the area Don't clean up floodwater by dumping it into the sink or toilet

 

This video provides some additional tips for how to avoid septic tank flooding and what to do if your system does flood:

 

Following these tips will help septic system homeowners to be prepared in the event of a flood and protect the septic system from further damages. If you need more specific advice or assistance with your septic system, contact your local health department for a list of septic system contractors in your area.

Featured Video: Regional Collaboration for Clean Water in York County

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Over 500 communities in the Chesapeake Bay watershed are working to meet NPDES permit standards for stormwater discharges from their municipal separate storm sewer systems (MS4s). MS4s that discharge to impaired surface waters or directly to the Bay are required to develop Pollutant Reduction or TMDL Plans. Meeting these requirements while also addressing important local issues such as increased flooding can be a challenge for any municipality, regardless of size.

However, Pennsylvania's York County has proven that there is strength in numbers. This video from MOST (Municipal Online Stormwater Training Center, an initiative of the University Of Maryland's Environmental Finance Center) features Felicia Dell, the director of the York County Planning Commission discussing how municipalities in her county banded together in a consortium to attract funding, and then distributed this funding in an equitable way to construct projects that would benefit all.

Hurricanes, Flooding and Wastewater Plants: What Have We Learned?

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In recent months, there have been dozens of reports of wastewater treatment plants that have flooded due to heavy hurricane rains and storm surges in Florida, Texas, Puerto Rico and beyond. Both the sheer number of plants affected, and the extent and duration of the flooding have posed significant public health and technical challenges, often stretching communities to their limits

To add to these problems, many rural utilities were already struggling to keep their systems operating before the storms struck, so costly, complicated repairs or replacements of damaged infrastructure is simply not an option. For example, Patton Village, Texas had just completed a new wastewater plant  the first of its kind in their community — before Hurricane Harvey struck. Now they can only hope that USDA/FEMA emergency funding will be available to help repair the damage. And even once the systems are up and running again, it is not a given that water systems can count on water rate income to help with their O&M bills - many residents have fled their flood-damaged homes for good.  

The sad truth is that lately, floods have been affecting wastewater plants with unfortunate regularity, and not just in hurricane-prone areas. For example, in Central Illinois, the small town of Hutsonville's wastewater treatment plant has flooded 3 times in the last 2 years, up from once every 5 years, according to its contract operator Shannon Woodward of Connor & Connor, Inc.

Woodward's first piece of advice is not to build on a floodplain, but he also acknowledges that many communities do not have the capital funds for effective protective measures or relocation, and so operators must deal with the hand they are given. His second piece of advice: "Make sure all electrical controls, switch gears and transformers are above the flood stage. That way, when the flood waters subside, you don't have equipment loss and can get back into operation — even if it takes 3 to 6 weeks for the waters to recede." 

Mason City, another small town in Illinois, was able to fund improvements after a flood in 2008 cut off the town’s water supply and nearly overflowed the capacity of its wastewater system. The following year, the city built a stone wall around the water plant, installed flood sensors on the local river, and built effluent pumping stations for the wastewater plant. 

And this article tells the damage and recovery stories of two flooded wastewater plants in Rhode Island. According to the operators of these plants, it is essential to have a flood plan, even if you think your facility is protected. In addition, they maintain it is important to involve wastewater treatment personnel in emergency response exercises or in the incident command structure. On a practical level, the operators encourage SCADA systems to be elevated on the second floor in the operations building if possible. And lastly, they recommend you back up your files and documents electronically. Papers get wet, they say: move them to a dry storage facility. 

Finally, while every community has different characteristics and needs, there are some universal preparedness strategies for wastewater plants. The US EPA recommends practicing mitigation options as the best way to prevent floodwater from invasively appearing. Some of these options include crafting barriers around key assets, having an emergency back-up generator, and keeping key electrical equipment elevated. You can learn more about these options here, or you can watch this helpful video. In addition, many states have their own guidances, such as this one from Minnesota’s Pollution Control Agency.